Dental model trimmer



2 Sheets-Sheet 1 Filed June 1, 1958 INVENTOR.

I ATTORNEY.

July 15, 1941.

a 5: 0 2% 38 firm 3 R. BUNCH DENTAL MODEL TRIMMER Filed June- 1, 1938 Ray 2 Sheets-Sheet '2 INVENTOR.

Patented July 15, 1941 V d V Ray Bunch s-Les Angeles, Calif. rran e we 1 a see! n- 1 1 431? I I 3 Claims. (01. si -428 My in ent relates generally e in n ei 2 .re s ??9?! tekeeee w mi chines and more particularly those'hiachl es gnth 3 io'fFi'g. v

employing abrading' Wheels and which areused aperspectiv view ofthe two side walls in dental laboratories for the accurate andrg fpid i'th' hd mg of'the'n a ime.

triimning of the plaster casts made by dentists 5 Fi "5 is'a' de il s cfib' showin the means inthe practiee'of warm. M J

The principal'objectsof my invention-are to v s y d 7 generally improve upon and simplify the con-- ile g- 'fi wof watermte the b e H struction of the existing typ set denyai nqu fsliaftl parts contained therein may beradily re d trimmers and to provide a relatively son'- l lf g'. fiisadetailsection taken onthe lin 5 6 pact and readily portable machine havingiapair of; 5 of motor driven grinding disks; and which latter, by their abrasive amen, very rapidly 'arid f- 7 s gr r nfi ve i w o e or 5119-. s tin penetr te a d .nhepo' i w iitfi fectively trim the dental casts that'are moved .S vd, mete abli 'sunp id. into engagement with the faces of said Fig! 3 is a detail ll l iflw s win the disks by the operator. V moans employed for delivjriiifgj ets of wateiofito Further objects of my invention are to provide the grindingjdisks." simple and efiicient means for delivering 'jets of Reigning v by Iiume water onto the abrading faces of theigr nding disks in order to wash awaythe cuttingsfrom the work and to provide means for carrying away from themachihe the water and cuttings; fur ther, to arrange the motor and the grinding disks carried thereby within 'a housing, which latter is mounted for swinging m yeui'entgfi a base in order that the position of the oiusi ng and drawings "which n s s rres ee t i' i iqn so as to bring either one of" the grinding yvfirs into position for use, and, further,to mount on the reversible housing adjustable supp k the work while the same is in engagehl o the grinding disks. Y Further objects of my invention are to provide simple and efiicient means whereby the evenue housing that carries the motor and grinding o s ree s r" 61 m e u cle; 9t p pes L3 to theoiiterlendsp'f which en dlflex ibl us lhai erij i f the wheels is firmly hem while in w1 0m of tsaeu e ji ifl fi e or operative positions, so that therewill no rotary movement of the housing and the grinding ,with and pro e i u war l of t e se tubularffibsfbi' 1e 4 hat serves a 'a ear'i'ngl for a pas 1,5, we end of the 1, tter resting at" sunrise Ts wheels while the latter are engaged bythe casts that projects inwardly fromthe' lower portion of as the same are being trimmed, and, furthenfto the post or standard 4. o provide means whereby the water delivered onto F med i the iQ lfie f a fl .Qf theinterinediate the abrasive faces of thegrindingdisks'ispre- IQQ PQ IQ film post l5 is a'fc'irc iumfer vented from splashing outwardly throughthe groqye Hand positioned therein v openings in the side walls of thehouisingflan d quate neniber 18 that functions'ias' a. rak hr which n n t e casts arem v d-int 9 lirelient'th os rom mating engagement with the grinding wheels. Screw seated in the ,wall or amara?! A further object of my'invention is to provide means for controlling and regulating the pressure of the water that delivered to the abrasive S t ep e ipheryof the post l5 within faces of the grinding disks. {nay b? accurately regulated r With the foregoing and other objects in ,view upp r'endjjof standard'llql i'siucut away to dj j i 10f. pressure of the my invention consists in certain novel featuresof f oriin anfjoppositely disposed pair of shouldef 29'', construction and arrangementsof parts that will and which shoulders function as stops ftl'iat afe be hereinafter more fully described an c l in ed engaged by stud 2| e projectgo a i and illustrated in the accompanying dr avv ings, in which: Fig. 1 is a vertical section taken through the center of a dental model trimmer constructed in accordance with my invention.

Fig. 2 is a sideelevational view of theomac l in e.

i nstruction. just described .proyidesmeans g emer m r mh ft f 7 '.both dire'ctions and'berrnit' th 4 lower portion of a bracket 25, the outer portion of which :bracket projects upwardly from plate 22.

Removably secured to bracket 25 is a conventional water pressure regulating valve 26 and.

leading thereto is a flexible watersupplytube 21. that extends downwardly through tubular post l to a suitable source of water supply, for in,- stance, the water service main.

= This regulating valve 26 is for the purpose of cutting down the pressure of the water that is delivered through supply line 21 and equalizing the pressure of the water that passes from said valve to the cutting disks.

The cable 28 that carries the electric conductors to and from the motor 23 extends through tubular post I5. Portions of the bearings 29 for the motor shaft 30 project beyond the ends of the motor housing and removably positioned upon said projecting portions are collars 3! that are formed integral with the central portions ofcircular plates 32, which latter serve as the inside end walls for the housin that encloses the motor and the grinding wheels.

Formed integral with the edges'of the disk 32 are outwardly presented flanges 33 and removably secured to the outer edges of these flanges are disks or plates 34 that serve as the outer end walls of the grinding wheel housing; The narrow spaces between the-inner and outer end walls 32 and 34 provide chambers for the grinding wheels that are carried by the motor shaft.

The means employed for securing the grinding wheels to the ends of the motor shaft is illustrated in Fig. 5 and such means includes an inner disk 35 that is secured to the motor shaft 30 by a set screw 36 and an outer disk 31 that is secured to inner disk 35 by screws such as 38.

A grinding wheel 39 of suitable abrasive material is clamped between the disks 35 and 31 and the central portion of each disk is provided with an opening 43 for the reception of the hub portion of disk 35 and with apertures 4| forthe reception of the screws 38. wheel is clamped between the disks 35 and 31 it overlies screw 33, thereby preventing the latter from becoming loose and unscrewing from hub of disk 35.

I prefer to provide grinding wheels having different degrees of abrasive qualities, for instance, one grinding wheel is formed of coarser material than the other so as to rapidly cut and-grind the work, while the other wheel is formed of finer material or material having qualities for producing a smooth finishing cut.

Formed in the central portion of each inner end disk 32 around the central openings through which the motor shaft 30 passes is a narrow annular chamber 42 and projecting into said chamber from the inner face of the adjacent disk 35 is'aflange 43 that decreases in width toward its outer edge. 1

Leading from the lower portion of the annular chamber 42 downwardly and outwardly to the outer face of the inner end wall 32 is a duct 44 which enables water and cuttings carried thereby to discharge from the annular chamber downwardly into and through the space between the inner and outer end walls 32 and 39. During ro- When the grinding tation of the cutting disk any water that flows downwardly over the inner face of disk must necessarily pass over the tapered flange 43 and by centrifugal force this water will be thrown outwardly into the annular chamber 43 and discharge from the lower portion thereof through duct 44.

Formed through each outer end wall or plate 34 to the side of and below the axis of the grindingwheels, are openings 45 that permit the casts 'to'bemoved' into contact with the outer faces of the grinding wheels; and in order to prevent the water that is delivered to the grinding wheels from splashing outwardly through the openings 45, narrow channels 46 that function as gutters are, formed on the inner faces of the plates 34 above'and to the sides of the openings 45 (see Fig.f 4).

Leadingfrom the lower portion of the equalizer valve-26 are tubes 41 that extend downwardly, thence outwardly beneath the pairs of end walls 32 and34; thence upwardly and the upper ends of said'tubes carryjet nozzles 48 that areseated in the outer end wall 34. The apertures in the jet nozzles 48 are arranged so that they discharge jets of water downwardly onto the outer faces of the grinding wheels (see Fig. 8)

The openings 45 in the outer end walls 34 0ccupy the same relative positions in said end Walls and thus when casts are inserted through the openings 45 and pressed against the grinding wheelsgthe pressure transmitted through said wheels, the motor, the table and the tubular post l5; will be applied by the stud 2| to one of the shoulders 23, and thus the post I 5 and parts carried thereby, including the motor and the housing, will be firmly held while a cast is being pressed against either grinding wheel.

Detachably secured to the outer faces of the outer end walls 34 below the openings 45 therein are inverted L-shaped brackets 49 positioned so that the upper faces of their horizontal portions lie flush with the lower edges of the openings 45.

Positioned on each bracket is a horizontally disposed cast-supporting table 50 and formed integral with and depending from the underside of each table is a lug 5| that projects through an opening 52 formed through the bracket.

Positionedon the underside of the bracket 49 is 'a washer 53 and passing therethrough and screw seated in the lug 5| is a screw or bolt 54 which firmly secures the Work supporting table to the bracket.

In order to accurately adjust the tables 50 on the brackets, screws 55 are seated in the outer ends of the horizontal portions of the brackets 49with the ends of said screws bearing against the undersides of the tables 50. Each screw 55 carries" a lock nut 56 which, when tightened against the under face of the bracket 43 secures the screw in its adjusted position and consequently holds the table in its adjusted position.

Suitably secured to the I outer faces of the flanges 33 on the inner end .walls 32 is a circumferential wall 51 Which,'together with the walls 32 and34, provides a substantially drum-shaped housing that encloses the motor and the parts that support same. The ends of this circumferential wall terminate at the bottom of the housing and said ends are spaced a suflicient distance apart for the accommodation of the tubes 41 and for the accommodation of drainage tubes 58 that lead from the bottoms of the chambers between the end walls 32 and 34 into the pocket I2 that is formed in base l0. These drainage tubes carry the water and cuttings from the chambers between the end walls 32 and 34 into the pocket l2 and said water and cuttings discharge from said pocket through the waste outlet l3.

Seated in the upper portion of the circumferential wall 57 is a conventional switch 59 that is located in the motor circuit and which controls the flow of current through said circuit to said motor.

In the operation of my improved dental model trimmer, switch 59 is manipulated to close the circuit to the motor and as the latter operates, the grinding wheels 39 carried by the ends of the motor shaft rotates at high speed in the chambers between the end walls 32 and 34. Water is permitted to flow through tube 21 to the equaliz-er valve 25 and water at uniform and reduced pressure, passes from the equalizer valve through tubes 4'! and is discharged from the jet nozzles 48 directly onto the outer faces of the grinding wheels. Equalizer valve 26 may be located on either end of tube 21.

The dental casts are placed on the tables 58 and moved inwardly through the openings 45 in the outer end walls 34 into direct contact with the outer faces of the grinding wheels and as a result of the abrasive action of the wheels on the casts the latter are trimmed to the desired degree and shape.

As heretofore described the pressure imparted to the casts during the grinding and trimming operations is transmitted to the stud 2! which bears against the solid shoulder 25], thereby firmly holding the motor and housing during the cast trimming operations.

The water delivered onto the surfaces of the grinding wheels washes the cuttings downwardly into the lower portions of the chambers between the end walls 32 and 34 and such water and cut tings after passing through tubes 58 and pocket l2 discharge through the waste outlet l3. This arrangement is particularly advantageous inasmuch as all dust arising from the cutting of the casts and which would be injurious to the health of the operator is eliminated.

During the operations incident to the grinding and trimming of dental casts and the like, the motor containing housing may be swung halfway around on the base to bring the desired grinding wheel into position to be engaged by the work and thus it is not necessary to turn the complete machine half-way around or for the workman to move from one side of the machine to the other while the casts are being cut or trimmed.

Thus it will be seen that I have provided a dental model trimmer that is relatively simple in construction, inexpensive of manufacture, and very effective in performing the functions for which it is intended.

While I have described my improved grinding machine as being especially applicable for use in grinding and trimming dental casts, it will be understood that the machine with very few, if any, changes or modifications may be advantageously employed for grinding any non-metallic or metallic substances or articles.

The machine is compact, capable of being readily moved from one position to another, thus facilitating the handling and transportation; and

through the abrasive action of the grinding wheels upon the work, the time, labor, and consequent expense in the trimming of dental models and the like are minimized; and at the same time accuracy in the cutting and trimming of the casts is insured.

It will be understood that minor changes in the size, form and construction of the various parts of my improved dental model trimmer may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. In a dental model trimmer, a base, a vertically disposed post mounted for limited rotary motion on said base, a motor supported by said post, grinding wheels carried by the end portions of the shaft of said motor, a housing enclosing said motor and movable therewith, partitions arranged within said housing and dividing the space therein into a centrally arranged motor chamber and separate chambers for said grinding wheels, means having a portion extending through the vertically disposed post for delivering water to the outer faces of said grinding wheels there being a pocket formed in the top of said base, means for conducting water from the lower portions of the grinding wheels chambers to said pocket, there being openings formed in said housing for exposing portions of said grinding wheels, and work-receiving tables secured to said housing below the openings therein.

2. In a dental model trimmer, a base, a vertically disposed post mounted for rotary movement on said base, a motor carried by said post, a housing carried by and enclosing 'said motor, said housing having an end wall, a grinding wheel carried by the shaft of the motor within said housing, a partition arranged within said housing between said motor and said grinding wheel, the end wall of the housing being provided with an opening that exposes a portion of the outer face of saidgrinding wheel, a work support on the exterior of the housing below the opening therein, means for delivering water onto said grinding wheel there being a pocket formed in the top of said base, means for conducting water from the lower portion of the grinding wheel chamber in the housing to said pocket, and a gutter formed on the inner face of the end wall of the housing above and to the sides of the opening therein.

3. In a dental model trimmer, a base, a vertically disposed post mounted for rotation on said base, a motor carried by said post, grinding wheels carried by the shaft of said motor, a housing supported by said motor and enclosing said grinding wheels and said motor, partitions arranged within said housing and dividing the space therein into a centrally arranged motor chamber and grinding wheel chambers, means for delivering water to said grinding wheels there being a pocket formed in the top of said base, means for conducting water from the lower portions of the grinding wheels chambers to said pocket, means for limiting the rotary motion of the post in both directions, and adjustable means for controlling the rotary motion of said post.

RAY BUN 

